1. 1 PHYSICAL PROPERTIES OF MATTER Boiling Points & Melting Points

2. 2 Observe and measure characteristic properties of substances that remain constant such as boiling points and melting points. (5.7 D)

3. 3 Key Vocabulary Terms Solid: The state of matter that has a definite shape and a definite volume. Liquid: The state of matter that has a definite volume but no definite shape. Gas: The state of matter that does not have a definite shape or volume. Friction: A force that opposes, or acts against, motion when two surfaces rub against each other. Temperature: The average kinetic energy of all the molecules in an object; the amount of hotness or coldness in a substance.

4. 4 Boiling point: The temperature at which a liquid boils. Freezing point: The temperature at which a liquid solidifies (changes into a solid). Melting point: The temperature at which a solid melts (changes into a liquid). Radiation: The transfer of thermal energy (heat) by electromagnetic waves. Example: Energy from the Sun travels through space by means of radiation to reach the Earth’s surface.

5. 5 Convection: The transfer of heat as the result of the mixing of a liquid or a gas. They produce circular currents or movements within a liquid (or a gas) due to different densities of the hotter and cooler areas of the material. Conduction: The direct transfer of heat through two objects that touch. The movement of heat from areas of higher temperature (more active atoms bouncing off one another) to areas of lower temperature. Electromagnetic waves: Refers to energy in the form of radio waves, infrared light, visible light, ultraviolet light, x-rays, and gamma rays. Density: The concentration of matter in an object.

6. 6 Phases of Matter Solid: The state of matter that has a definite shape and a definite volume. Liquid: The state of matter that has a definite volume but no definite shape. WATER

7. 7 Phases of Matter Gas: The state of matter that does not have a definite shape or volume. gas The water boils and changes from a liquid to a gas.

8. 8 Concepts to Remember… Properties of Matter- In order to accurately identify a particular type of pure matter scientists can classify the matter according to specific characteristics or attributes. If you had a glass of an unknown liquid you could easily identify the liquid by testing some of its properties of matter. Mystery Liquid It has a density of 1 g/cm 3 It has a boiling point of 100° Celsius!

9. 9 Concepts to Remember… Temperature- The hotness or coldness of matter. The hotness or coldness is determined by the presence or lack of heat. The fire has a much higher temperature and moves at a faster rate than the particles of ice (they are just vibrating). The heat from the match will travel to the ice by conduction, causing the particles of ice to speed up and thus begin to melt. A lit match

10. 10 B O I L I N G P O I N T The temperature at which a liquid boils. The temperature at which a liquid changes into a gas. The boiling point is dependent on pressure. FAST FACT! The boiling point of water at sea level is 100 ° Celsius. On top of Mount Everest the boiling point of water is 69 ° Celsius. This happens because of the difference in pressure.

11. 11 M E L T I N G P O I N T The temperature at which a solid melts (changes into a liquid). The reverse temperature change of the melting point is the freezing point. FAST FACT! Adding salt to water changes the physical properties of water. It lowers its melting point (as ice) and raises its boiling point.

12. 12 O bserving and M easuring A ctivity Materials Needed Safety goggles Glass beaker Thermometer Hot Plate Ice Stopwatch

13. 13 SS S cience S afety In this activity you will be working with a hot plate. It is very important that you wear safety goggles while working with the hot plate. Tie back or secure long hair or dangling clothing or jewelry. DO NOT TOUCH THE BURNER ON THE HOT PLATE! Turn off the hot plate and remove the thermometer before all of the water evaporates.

14. 14 1.Put on your safety goggles. 2.Put 3-5 ice cubes into the beaker. 3.Place the thermometer in the middle of the beaker of ice. 4.Place the beaker onto the hot plate. 5.Turn the hot plate on and record all observations. Observing and Measuring

15. 15 Observing and Measuring Time Elapsed Temperature (° C)Observations 2 minutes 4 minutes 6 minutes 8 minutes 10 minutes 12 minutes

16. 16 Making Observations 1.Describe each picture in Figure 1. 2.Describe the changes that take place between step 1 and 3. 3.Describe the change in temperature between each stage. 4.What do you notice about the temperature between step 3 and step 4? 5.What would be a good title for Figure 1? 1 2 34 FIGURE 1

17. 17 Making Observations 1.Describe each picture in Figure 2. 2.Describe the changes that take place. 3.What temperature changes occur between stage 1 and stage 3? 4.What would be a good title for Figure 2? 123 456 78 9 FIGURE 2